SU1342419A3 - Method of producing 6-methyl-3,4-dihydro-1,2,3-oxathiazine-4-on-2,2-dioxide as potassium salt thereof - Google Patents

Abstract

6-Methyl-3,4-dihydro-1,2,3-oxathiazin-4-one 2,2-dioxide is prepared by reaction of acetoacetamide with at least approximately twice the molar amount of SO3 per mole of acetoacetamide, if appropriate in an inert inorganic or organic solvent. Relevant salts can be obtained, using bases, from the product which results in the form of the acid. The non-toxic salts, in particular the potassium salt, are valuable synthetic sweeteners.

Description

The invention relates to a process for the preparation of 6-methyl-3, 4-dihydro-1,2,3-oxathiazin-4-one-2,2-dioxide as its potassium salt, which has a sweet taste and is used in the food industry.

The aim of the invention is to simplify the process and increase its efficiency and safety.

This goal is achieved by reacting acetoacetamide with sulfuric anhydride or with a complex of sulfuric anhydride with a tertiary amine as the oxide of sulfur with a molar ratio of reagents based on sulfuric anhydride 1: (4-8), respectively, in the medium of halogenated aliphatic hydrocarbon as inert organic solvent.

Example 1, K8 ml (200 mmol) of liquid SO, in 20 ml of CTCS at -60 ° C, 5.1 g (50 mmol) of acetocetamide in 50 ml are added dropwise. After 2 hours, 50 ml of ethyl acetate and 50 ml of water are added to the solution. The organic phase is separated and the aqueous is extracted twice more with ethyl acetate. The combined organic phases are concentrated after drying over sodium sulfate and dissolved in methanol. When the solution is neutralized with a methanol solution of KOH, the 6-methyl-3, 4-dihydro-1,2,3-oxathiazine-4-one-2,2-dioxide potassium salt precipitates. Yield 3, g (31%).

Example 2. 15.9 g (100 mmol) of pyridine-30z complex and 5.1 g (50 mmol) of acetoacetamide in 100 ml of CHjCli are stirred for 17 hours at room temperature. Reaction — then for 10 min at to a solution of 12 ml

measure 11, 8

P

1 with the addition of 90 ml. Output

g (65%).

R im e 4. To 15.2 ml (110 mmol

ten

triethylamine in 50 ml of 1, 2-dichloroethane at -40 ° C was added dropwise a solution of 4 ml (100 mmol) SO, in 20 ml,. The solution is boiled for 4 hours with 5.1 g (50 mmol) of acetoacetamide. After that, it is cooled and at-C0 for 1 h they are added dropwise to a solution of 2.4 ml (60 mmol) of SO, and for 1 h they are dropped to a solution of 2.4 ml (60 mmol) of SO, in 50 ml of One- temporarily after 12, 24, 36, 48 minutes, 2.4 ml (60 mmol) of 80 ml each are added. After 20 minutes, it is treated as in Example 1. The yield is 1 g (10%).

PRI me R 5. K13,2 ml (110 mmol) of 2,4-collidine in 50 ml with a drop of 4 ml.

20

-40 ° C

(100 mmol) SO, in 20 ml of 012. After the addition of 5.1 g (50 mmol) of acetoacetamide, it is stirred for 17 h

25 at room temperature. This solution at -30 ° C for I h is added dropwise to a solution of 2.4 ml (60 mmol) SOj in 50 ml. At the same time after 12, 24, 36, 48 minutes add

30 2.4 ml (60 mmol) 80 ,. After 20 minutes, it was worked up as in Example 1. Yield 9 g (90%).

Example K8 ml (200 mmol) of liquid SOj in 150 ml for 60 min at -25 ° C solution is added dropwise

35

5.1 g (50 mmol) of acetoacetamide and 6.9 ml of triztilamine in 100 ml and further stirred for 90 min at. Axis mixture processing

-30 C added

(300 mmol) 80:

50 ml,

40 is based on example I. Yield 4.1 g (41%).

Example. The treatment was carried out analogously to Example 6; however, instead of 8 ml (200 mmol) of liquid 80, using 20 minutes, the solution was treated in the same way as 45 g of 16 g (200 mmol) of solid SO, example 1. The yield was 7.9 g (79%). The output of 3.7 g (37%).

Example8. To a mixture of 15.5 ml (250 mmol 80z) of 65% oleum in 150 ml at -25 ° C for gg 30 MIN, a solution of 5.1 g (50 mmol) of acetoacetamide in 100 ml is added dropwise.

Example A solution of 4 ml (100 mmol) 80 v-20 ml is added to a 13.2 ml (PO mmol) of 2,4,6-collidine in 50 ml at -40 ° C. After that, the solution with 9.1 g (90 mmol) of acetoacetamide is stirred for 23 hours at room temperature. Then the solution at -30 ° C for 1 h is added dropwise to 4.4 ml (PO mmol) S03 in 200 ml. At the same time, after 12, 24, 36 and 48 minutes, respectively, 4.4 ml (PO mmol) 80z are added. . After 20 minutes, process as in CH-jClj and further stir for 60 minutes at -25 ° C. The treatment is carried out as in Example 1. You have a gg stroke of 2.3 g (23%). Comparative example.

35.42 g (250 mmol) are introduced into 250 ml of CH2. C12. At -25 ° C for 60 minutes, added dropwise to the resulting plant.

measure 11, 8

P

Claims (2)

1. The method of producing 6-methyl-3,4- 1: (4-8), respectively, in the medium of halo-dihydro-1,2,3-oxathiazin-4-one-2,2-di-15 genated aliphatic carbon oxide in the form of its potassium salt in the hydrocarbon as an inert by the interaction of the acetoacetyl compound solvent, nor with the oxide compound of sulfur in er-. 2. The method according to claim 1, about tl and h and the inert organic solvent solution, and the fact that as halo at a temperature from up to com- bined, genetically aliphatic carbonate with allocation of the target product is take methylene chloride.